Takes about 20 seconds
Settings
Server: the nearest Cloudflare data centre, chosen automatically. Load: speed.cloudflare.com.
How we calculate jitter: we take the idle round trips (about 20–25 web requests to the nearest Cloudflare data centre, one every 0.2 seconds, after 2 warm-up requests) and average the difference between each round trip and the next. Example: 20, 24 and 21 ms give differences of 4 and 3 ms, so jitter is 3.5 ms. Full method.
Jitter in plain words
Jitter is how much your delay wobbles. If one packet takes 20 ms and the next takes 60 ms, your connection is jittery even if the average looks fine. The IETF calls this "packet delay variation" and defines how to measure it in RFC 3393 and RFC 5481.
Why jitter matters for calls and games
Voice and video apps play sound and pictures in a steady rhythm. When packets arrive unevenly, the app either waits longer (adding delay) or plays gaps and robotic audio. Games feel the same as stutter or "rubber-banding". A connection with slightly higher but steady ping often feels better than a low but jumpy one.
Common causes of high jitter
- Wi‑Fi interference or a weak signal.
- Full router queues while others upload or download (bufferbloat), which the bufferbloat test shows directly.
- Congestion on your provider's network at busy hours.
- Background apps on your own device, such as updates and cloud sync.
How to bring jitter down
Use a cable for important calls and games, pause big transfers, and if jitter rises mainly under load, turn on Smart Queue Management as described in How to fix bufferbloat.
What’s good? Our colour guide
| Jitter | Range |
|---|---|
| Good | up to 10 ms |
| OK | more than 10, up to 30 ms |
| High | more than 30 ms |
These are the labels this test uses, as a rough guide, not an official standard.
Other tests
FAQ
What is a good jitter value?
Lower is better. Small variations of a few milliseconds go unnoticed; larger swings start to show up in calls and games. Our colour labels for jitter: Good up to 10 ms, OK up to 30 ms, High above 30 ms.
Is jitter the same as packet loss?
No. Jitter is uneven timing; packet loss is data that never arrives. Check both with the packet loss test.
Can a speed test show jitter?
Some do. This page focuses only on timing steadiness, so you can test it on its own.